In an interview director Harry Bromley Davenport said star Jan-Michael Vincent was extremely difficult to work with. Vincent didn't care about the film and thus didn't memorize his lines. Davenport was then forced to feed every line to him while filming each scene.
This sequel has nothing to do the original Xtro (1982). This is because director Harry Bromley Davenport somehow retained the rights to the name Xtro but not the story rights. Needing money he enlisted writers to write a completely different film and only use the Xtro name to capitalize on the cult success of the original.